Simplify the following expression: $n = \dfrac{6z - 8}{3z} + \dfrac{-9z + 7}{3z}$
Since the expressions have the same denominator we simply combine the numerators: $n = \dfrac{6z - 8 - 9z + 7}{3z}$ Combine like terms: $n = \dfrac{-3z - 1}{3z}$